Polymers and chemically amplified positive resist compositions

Abstract

A polymer comprising recurring units of formula (1) is provided wherein some hydrogen atoms of phenolic hydroxyl groups and/or carboxyl groups are replaced by acid labile groups. The polymer is crosslinked with a crosslinking group having a C--O--C linkage resulting from reaction of some of the remaining phenolic hydroxyl groups and/or carboxyl groups with an alkenyl ether compound or halogenated alkyl ether compound. The amount of the acid labile group and the crosslinking group combined is on the average from more than 0 mol % to 80 mol % of the entirety of the phenolic hydroxyl group and carboxyl group. The polymer has Mw of 1,000-500,000. R 1 is H or methyl, R 2 is C 1 -C 8 alkyl, R 3 is H, R 4 is --COOR 5 , C 1 -C 5 alkyl or phenyl, or R 3 and R 4 , taken together, may form --COOCO--, R 5 is H or C 1 -C 8 alkyl, x and y are integers satisfying x+y≦5, p and q are positive numbers satisfying p+q=1 and 0<q/(p+q)≦0.9. A chemically amplified positive resist composition comprising the polymer as a base resin has high sensitivity and resolution and forms resist patterns having plasma etching resistance, heat resistance, overhang prevention, and dimensional controllability.

What is claimed is: 
     
       1. A polymer comprising recurring units of formula (1), wherein at least one of the hydrogen atoms of phenolic hydroxyl and/or carboxyl is independently replaced by an acid labile group,   the polymer is crosslinked within a molecule and/or between molecules with a crosslinking group having a C--O--C linkage resulting from reaction of some of the remaining phenolic hydroxyls and/or carboxyls with an alkenyl ether or halogenated alkyl ether,   the amount of the acid labile group and the crosslinking group combined is on the average from more than 0 mol % to 80 mol % of the entirety of the phenolic hydroxyl and carboxyl in formula (I), and the polymer has a weight average molecular weight of 1,000 to 500,000, wherein formula (1) is ##STR49## wherein R 1  is hydrogen or methyl, R 2  is a normal, branched or cyclic alkyl of 1 to 8 carbon atoms, R 3  is hydrogen, R 4  is --COOR 5 , R 5  is hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, x is 0 or a positive integer, y is a positive integer, the sum of x+y is up to 5, p and q are positive numbers satisfying p+q=1 and 0<q/(p+q)≦0.9.     
     
     
       2. The polymer of claim 1 comprising recurring units of formula (2), wherein the polymer is crosslinked within a molecule and/or between molecules with a crosslinking group having a C--O--C linkage resulting from reaction of some of the phenolic hydroxyls and/or carboxyls represented by R with an alkenyl ether or halogenated alkyl ether,   the amount of the acid labile group and the crosslinking group combined is on the average from more than 0 mol % to 80 mol % of the entirety of the phenolic hydroxyl and carboxyl in a formula (1), and   the polymer has a weight average molecular weight of 1,000 to 500,000, wherein formula (2) is ##STR50## wherein R is hydroxyl or OR 6 , at least one R is hydroxyl, R 1  is hydrogen or methyl, R 2  is normal, branched or cyclic alkyl of 1 to 8 carbon atoms, R 3  is hydrogen, R 4  is --COOR 5 , R 5  is hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, R 6  is an acid labile group, x is 0 or a positive integer, y is a positive integer, the sum of x+y is up to 5, k and m are 0 or positive integers, n is a positive integer, the sum of k+m+n is up to 5, p1 and p2 are positive numbers, q1 and q2 are 0 or positive numbers, q1 and q2 are not equal to 0 at the same time, and p1, p2, q1 and q2 satisfy 0<p1/(p1+p2+q1+q2)<0.8,0<p2/(p1+p2+q1+q2)<0.8, 0<(p1+q2)/(p1+p2+q1+q2)<0.8, and p1+p2+q1+q2=1.     
     
     
       3. The polymer of claim 2 comprising recurring units of formula (3), some hydrogen atoms being eliminated from phenolic hydroxyls and/or carboxyls represented by R to leave oxygen atoms which are crosslinked with a crosslinking group having a C--O--C linkage of formula (4a) or (4b) within a molecule and/or between molecules,   the amount of the acid labile group and the crosslinking group combined being on the average from more then 0 mol % to 80 mol % of the entirety of the phenolic hydroxyl and carboxyl in formula (1), and   the polymer having a weight average molecular weight of 1,000 to 500,000, wherein formula (3) is ##STR51## wherein R is hydroxyl or OR 6 , R 1  is hydrogen or methyl, R 2  is normal, branched or cyclic alkyl of 1 to 8 carbon atoms, R 3  is hydrogen, R 4  is --COOR 5 , R 5  is hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, R 6  is of formula (5) or (6), tertiary alkyl of 4 to 20 carbon atoms, trialkylsilyl whose alkyl groups each have 1 to 6 carbon atoms or oxoalkyl of 4 to 20 carbon atoms, p11, p12 and p2 are positive numbers, q1 and q2 are 0 or positive numbers, q1 and q2 are not equal to 0 at the same time, and p11, p12, p2, q1 and q2 satisfy 0<p11/(p11+p12+p2+q1+q2)<0.8, 0<p2/(p11+p12+p2+q1+q2)<0.8, 0(p11+p12+q2)/(p11+p12+p2+q1+q2)<0.8, and p11+p12+p2+q1+q2=1, x is 0 or a positive integer, y is a positive integer, the sum of x+y is up to 5, k and m are 0 or positive integers, n is a positive integer, the sum of k+m+n is up to 5,   wherein formula (4a) and (4b) are ##STR52## wherein R 7  and R 8  each are hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, or R 7  and R 8 , taken together, form a ring, with the proviso that each of R 7  and R 8  is normal or branched alkylene of 1 to 8 carbon atoms when they form a ring, R 9  is normal or branched alkylene of 1 to 10 carbon atoms, d is 0 or an integer of 1 to 10, A is a c-valent aliphatic or alicyclic saturated hydrocarbon, aromatic hydrocarbon or heterocycle of 1 to 50 carbon atoms, which may have an intervening hetero atom and in which the hydrogen atom attached to a carbon atom may be partially replaced by hydroxyl, carboxyl, acyl or fluorine, B is --CO--O--, --NHCO--O or --NHCON--, c is an integer of 2 to 8, and c' is an integer of 1 to 7,   and wherein formula (5) and (6) are ##STR53## wherein R 10  and R 11  each are hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, R 12  is monovalent hydrocarbon of 1 to 18 carbon atoms which may have a hetero atom, or R 10  and R 11 , and R 10  and R 12 , or R 11  and R 12 , taken together, form a ring, with the proviso that each of R 10 , R 11  and R 12  is normal or branched alkylene of 1 to 18 carbon atoms when the form a ring, R 13  is tertiary alkyl, of 4 to 20 carbon atoms, trialkylsilyl whose alkyls each have 1 to 6 carbon atoms, oxoalkyl of 4 to 20 carbon atoms or a group of formula (5), and a is an integer of 0 to 6.     
     
     
       4. The polymer of claim 3 wherein the crosslinking group having a C--O--C linkage of formula (4a) or (4b) is represented by formula (4a'") or (4b'"): ##STR54## wherein R 7  and R 8  each are hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, or R 7  and R 8 , taken together, form a ring, with the proviso that each of R 7  and R 8  is normal or branched alkylene of 1 to 8 carbon atoms when they form a ring, R 9  is normal or branched alkylene of 1 to 10 carbon atoms, d is 0 or an integer of 1 to 5, A' is c"-valent normal or branched alkylene, alkyltriyl or alkyltetrayl of 1 to 20 carbon atoms or arylene of 6 to 30 carbon atoms, which may have an intervening hetero atom and in which the hydrogen atom attached to a carbon atom may be partially replaced by hydroxyl, carboxyl, acyl or fluorine, B is --CO--O--, --NHCO--O-- or --NHCONH--, c" is an integer of 2 to 4, and c'" is an integer of 1 to 3. 
     
     
       5. A chemically amplified positive resist composition comprising (A) an organic solvent,   (B) a base resin in the form of the polymer of claim 1, and   (C) a photoacid generator.   
     
     
       6. The resist composition of claim 5 further comprising (D) another base resin in the form of a polymer comprising recurring units of formula (1), some of the hydrogen atoms of phenolic hydroxyls and/or carboxyls being replaced independently by an acid labile group in an average proportion of 0 mol % to 80 mol % of the entirety, said polymer having a weight average molecular weight of 3,000 to 300,000, wherein formula (1) is ##STR55## wherein R 1  is hydrogen or methyl, R 2  is normal, branched or cyclic alkyl of 1 to 8 carbon atoms, R 3  is hydrogen, R 4  is --COOR 5 , R 5  is hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, x is 0 or a positive integer, y is a positive integer, the sum of x+y is up to 5, p and q are positive numbers satisfying p+q=1 and 0<q/(p+q)≦0.9.     
     
     
       7. The resist composition of claim 5 further comprising (E) a dissolution regulator. 
     
     
       8. The resist composition of claim 5 further comprising (F) a basic compound. 
     
     
       9. The resist composition of claim 5 further comprising (G) an aromatic compound having .tbd.C--COOH. 
     
     
       10. The resist composition of claim 5 further comprising (H) a UV absorber. 
     
     
       11. The resist composition of claim 5 further comprising (I) an acetylene alcohol compound. 
     
     
       12. A chemically amplified positive resist composition comprising (A) an organic solvent,   (B) a base resin in the form of the polymer of claim 2, and   (C) a photoacid generator.   
     
     
       13. A chemically amplified positive resist composition comprising (A) an organic solvent,   (B) a base resin in the form of the polymer of claim 3, and   (C) a photoacid generator.   
     
     
       14. A chemically amplified positive resist composition comprising (A) an organic solvent,   (B) a base resin in the form of the polymer of claim 4, and   (C) a photoacid generator.   
     
     
       15. A method of making a polymer of formula (1) according to claim 1, comprising performing radical polymerization or living anion polymerization of monomers of formula (i), and/or (iii) ##STR56## wherein R 1 , R 2 , R 4 , x and y are as defined in claim 1. 
     
     
       16. A method of making a polymer of formula (2) according to claim 2, comprising performing radical polymerization or living anion polymerization of monomers of formula (i), (ii) and/or (iii) ##STR57## wherein R 1 , R 2 , R 4 , R 6 , x, y, k, m and n are as defined in claim 2. 
     
     
       17. The polymer of claim 1, wherein R 2  is an alkyl having 1-3 carbon atoms, said halogen of R 4  is Cl, Br, I or F, and y is 1 or 2. 
     
     
       18. The polymer of claim 2, wherein R 6  is a molecule of formula (5) or (6) ##STR58## wherein R 10  and R 11  each are hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, R 12  is monovalent hydrocarbon of 1 to 18 carbon atoms which may have a hetero atom, or R 10  and R 11 , R 10  and R 12 , or R 11  and R 12 , taken together, form a ring, with the proviso that each of R 10 , R 11  and R 12  is normal or branched alkylene of 1 to 18 carbon atoms when the form a ring, R 13  is tertiary alkyl of 4 to 20 carbon atoms, trialkylsilyl whose alkyls each have 1 to 6 carbon atoms, oxoalkyl of 4 to 20 carbon atoms or a group of formula (5), and a is an integer of 0 to 6, and wherein R 6  is of formula (5) or (6), tertiary alkyl of 4 to 20 carbon atoms, trialkylsilyl whose alkyl groups each have 1 to 6 carbon atoms or oxoalkyl of 4 to 20 carbon atoms.   
     
     
       19. The polymer of claim 2, wherein n=1 or 2, m=0 or 1, R 10  and R 11  are each alkyl having 1 to 5 carbon atoms,   R 12  has 1 to 8 carbon atoms,   R 10 , R 11 , R 12  are each alkylene group having 1 to 8 carbon atoms when they form a ring, and   R 13  has 4 to 10 carbon atoms.   
     
     
       20. The polymer of claim 1, wherein said crosslinking group has a C--O--C linkage of formula (4a) or (4b) with a molecule and/or between molecules ##STR59## wherein R 7  and R 8  each are hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, or R 7  and R 8 , taken together, form a ring, with the proviso that each of R 7  and R 8  is normal or branched alkylene of 1 to 8 carbon atoms when they form a ring, R 9  is normal or branched alkylene of 1 to 10 carbon atoms, d is 0 or an integer of 1 to 10, A is a c-valent aliphatic or alicyclic saturated hydrocarbon, aromatic hydrocarbon or heterocycle of 1 to 50 carbon atoms, which may have an intervening hetero atom and in which the hydrogen atom attached to a carbon atom may be partially replaced by hydroxyl, carboxyl, acyl or fluorine, B is --CO--O--, --NHCO--O or --NHCONH--, c is an integer of 2 to 8, and c' is an integer of 1 to 7. 
     
     
       21. The polymer of claim 2, wherein said crosslinking group has a C--O--C linkage of formula (4a) or (4b) with a molecule and/or between molecules ##STR60## wherein R 7  and R 8  each are hydrogen or normal, branched or cyclic alkyl of 1 to 8 carbon atoms, or R 7  and R 8 , taken together, form a ring, with the proviso that each of R 7  and R 8  is normal or branched alkylene of 1 to 8 carbon atoms when they form a ring, R 9  is normal or branched alkylene of 1 to 10 carbon atoms, d is 0 or an integer of 1 to 10, A is a c-valent aliphatic or alicyclic saturated hydrocarbon, aromatic hydrocarbon or heterocycle of 1 to 50 carbon atoms, which may have an intervening hetero atom and in which the hydrogen atom attached to a carbon atom may be partially replaced by hydroxyl, carboxyl, acyl or fluorine, B is --CO--O--, --NHCO--O or --NHCONH--, c is an integer of 2 to 8, and c' is an integer of 1 to 7. 
     
     
       22. The polymer of claim 1 wherein the amount of the acid labile group and the crosslinking group combined is from 2 to 50 mol % of the entirety of the phenolic hydroxyl and carboxyl groups in formula (1), and the weight average molecular weight of the polymer is 3,000 to 30,000. 
     
     
       23. The polymer of claim 3, wherein said intervening hetero atom of R 9  is O, NH, N(CH 3 ), S or SO 2 , and wherein said hetero atom of R 12  is O.   
     
     
       24. The polymer of claim 4, wherein said intervening hetero atom of R 9  is O, NH, N(CH 3 ), S or SO 2 .